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Pumped-storage hydroelectricity (PSH), or pumped hydroelectric energy storage (PHES), is a type of hydroelectric energy storage used by electric power systems for load balancing. A PSH system stores energy in the form of gravitational potential energy of water, pumped from a lower elevation reservoir to a higher elevation.
Storage capacity is the amount of energy extracted from an energy storage device or system; usually measured in joules or kilowatt-hours and their multiples, it may be given in number of hours of electricity production at power plant nameplate capacity; when storage is of primary type (i.e., thermal or pumped-water), output is sourced only with ...
If a moving fluid meets an object, it exerts a force on the object. Suppose that the fluid is a liquid, and the variables involved – under some conditions – are the: speed u, fluid density ρ, kinematic viscosity ν of the fluid, size of the body, expressed in terms of its wetted area A, and; drag force F d.
Marine energy, also known as ocean energy, ocean power, or marine and hydrokinetic energy, refers to energy harnessed from waves, tides, salinity gradients, and temperature differences in the ocean. The movement of water in the world's oceans stores vast amounts of kinetic energy , which can be converted into electricity to power homes ...
Hydropower (from Ancient Greek ὑδρο-, "water"), also known as water power or water energy, is the use of falling or fast-running water to produce electricity or to power machines. This is achieved by converting the gravitational potential or kinetic energy of a water source to produce power. [1] Hydropower is a method of sustainable energy ...
The stored energy is proportional to the ambient pressure in the depths of the sea. Problems considered during the construction of the hollow sphere were choosing a construction-type that withstands the high water-pressure and which is heavy enough to keep the buoyancy force lower than the gravitational force. [3]
Blue line: drag force; red line: inertia force; black line: total force according to the Morison equation. Note that the inertia force is in front of the phase of the drag force: the flow velocity is a sine wave, while the local acceleration is a cosine wave as a function of time.
The frequency at which vortex shedding takes place for a cylinder is related to the Strouhal number by the following equation: = Where is the dimensionless Strouhal number, is the vortex shedding frequency (Hz), is the diameter of the cylinder (m), and is the flow velocity (m/s).